Influence of interfacial oxygen on single-crystal magnetic tunnel junctions

The influence of adsorbed oxygen at the first interface of single-crystal Fe(001)/MgO(001)/Fe(001) magnetic tunnel junctions is investigated. Firstly, the adsorption kinetics of O2 on the Fe(001) surface is studied in the monolayer regime by X-ray photoelectrons spectroscopy and scanning tunnelling microscopy experiments. We show that different species exist at the oxidized surface. The tunnel magneto-resistance of oxygen-doped magnetic tunnel junctions is found to decrease but remains large even for oxygen coverages exceeding one monolayer